[bug #59536] Add support for wchar_t type

[avrs-admin]

Tue 24 Nov 2020 07:48:56 PM CET

wchar_t is not really supported by avr-libc.
However even in embedded electronics there are sometimes cases were working with wide chars becomes necessary.
To make this easier the C standard specifies a wchar.h header which provides wide variants of many other function specified in the standard library like strlen and printf

This issue was migrated from https://savannah.nongnu.org/bugs/?59536

[sprintersb]

There's at least one problem though. AVR-LibC's printf-like functions recognize %S as an ordinary string located in flash, as opposed to the standard that uses %S to specify wide strings.

[Krotti83]

AVR-LibC's printf-like functions recognize %S as an ordinary string located in flash, as opposed to the standard that uses %S to specify wide strings.

According the C99, C11 and C23 specification %ls (for strings) or %lc (for a single character) should be used for wchar_t. The aliases %S for %ls and %C for %lc are POSIX (SUSv2, SUSv3 and SUSv4) extensions, so far I know.